With an increasing emphasis on energy efficiency, attic insulation has often been supplemented by blown, loose-fill insulation, or by additional or thicker insulation bats to prevent heat loss in the winter and cool air loss in the summer. Unfortunately, thicker attic insulation can lead to poor air circulation when the spaces between the roof joists and the top wall plate of the building are closed or obstructed. These spaces must be left open to provide air flow between the soffit area and the attic space, for reducing excess humidity and heat, which have been known to deteriorate roofing and structural components. In order to keep this area open, baffled attic vents have been used.
The purpose of an attic vent is to prevent installed insulation, such as fiberglass bats, blankets, fiberglass and cellulose loose fill, from blocking the natural air flow from the ventilated soffit up through to the roof ridge vent or gable vents in the attic. Several attic baffled vents have been designed for this purpose. See, for example, U.S. Pat. No. U.S. Pat. No. 4,007,672 directed to a perforated block-style vent, U.S. Pat. No. 4,125,971 directed to a flat panel formed on site into an arch; U.S. Pat. No. 4,126,973 directed to a perforated block-style vent; U.S. Pat. No. 4,197,683 which is directed to the use of a vent board attached in the A-plane of a header board; U.S. Pat. No. 4,214,510 directed to a rolled sheet baffle design; U.S. Pat. No. 5,341,612 directed to the use of a longitudinal ridge in a roof vent for compressive stiffness; U.S. Pat. No. 5,596,847 directed to a vent having an integral transverse stiffening element integrated in the bottom offset wall; U.S. Pat. No. 5,600,928, directed to a vent having stiffeners in the form of saddles in the longitudinal ridges of the roof plane and gussets between offset, bottom surface and the inclined walls of the channel; U.S. Pat. No. 6,347,991, directed to a baffled vent having an integral hinge in a transverse direction, about 4-6 inches from one end; U.S. Pat. No. 6,346,040, directed to an integral vent and dam folded on-site from a flat sheet; and U.S. Pat. No. 6,357,185, directed to a vent having a sealable panel between the bottom of the baffle and the top of the header.
In addition, there are many commercial attic vents that are available for this purpose: PERMA-R® from Owens-Corning; CERTIVENT® from Diversifoam, Inc. A simple foam baffle available from Apache Products; DUROVENT® available from ADO Products; PROVENT® from an unnamed source; and products available from Pactiv; AEROVENT® from Shelter Enterprises, Inc.; and POLYVENT PLUS® from Moore Products, LLC.
Most of the above mentioned patented or commercial baffled vents are vacuumed-formed extruded polystyrene foam. These designs provide for an open air flow area required by most building codes, while providing the stiffness to resist collapsing when the insulation is installed.
The features used to stiffen such vents, such as ribs and longitudinal stiffeners, unfortunately also restrict air flow. In some cases, such a restriction is counter productive to the purpose of the vent, but is unknown to the homeowner.
Accordingly, there is a present need for a baffled air vent which has structural integrity in both width and length, without sacrificing air flow.